Cheapsy Third Axis

ArcheryFox

Member
I've noticed after switching my stabiliser setup around and some technique changes I'm getting some left misses downhill, and right uphill.
Guess I need to re-set my third axis.

Normally I'd borrow the Hamskea 'Easy Third Axis' tool from my club's resident kit monkey, but since we still aren't shooting yet that's not an option, and I can't justify the £55 or so the device costs, so this got me thinking...
I present to you the 'Cheapsy Third Axis' tool!

This consists of:
- A G-clamp (reasonable quality with a swivel shoe head to sit flat), about £4
- Mini spirit levels, about £4 for 5
- Blu-tack or plasticine, £pittence

ETA1.jpg


Once I put it together I set the axes of the bubble glued to the clamp by using two surfaces that I knew were already level, in this case my kitchen chair:

ETA2.jpgETA3.jpg

Once this is done it can be used in the same way as the Hamskea.
The mini levels came in a pack of 5, so I used these on the flat surfaces of the bow to get it level.
Checking sight arm is level
ETA4.jpg

Checking sight track is level:
ETA5.jpg

Checking third axis uphill direction (apologies for the poor quality, its hard to hold a bow in the hand, pointing upwards, keep it level, and operate a camera but you get the idea!):
ETA6.jpg


I'm sure I can't be the first to do this, but I haven't seen it before so thought I'd put it online.
This was all to use quickly this morning, but for future use I am considering using an epoxy to fix the bubble to the G-clamp permanently so that it doesn't move.

Any questions about specifics such as how to set the axes on the clamp etc. drop me a message or a reply.
 


geoffretired

Supporter
Supporter
I admire your attention to detail and the great pictures help hugely, too.
When testing all three axes, isn't it also possible to use parallel strips and right angle templates to reach the same conclusions?
I am thinking that archers might have easy access to right angle corners on sturdy card.
 


ArcheryFox

Member
I admire your attention to detail and the great pictures help hugely, too.
When testing all three axes, isn't it also possible to use parallel strips and right angle templates to reach the same conclusions?
I am thinking that archers might have easy access to right angle corners on sturdy card.
Thanks.

There are a few clever ways to set the axes, for example Bowfinger have a device that requires two apertures to line up.
This works well on their scope due to the long tunnel length, but like many accessories in archery, including the Hamskea, it is unnecessarily expensive.

What I like about the Hamskea, and my alternative, is that it is logical to use with minimal opportunity for user error.
Make the bow level*, strap the device on the part you want to level, is the device level? Yes - great news. No - adjust so it is.
It's also nice and straightforward to just be able to look at the device bubble and scope bubble and compare.

You should be able to do something with parallel lines, but I am not sure it would be as accurate or 'idiot-proof'.
Do you mean something like place a credit card on the flat arrow shelf and then try and line up the sight track with it?
This would work, but the degree you can get it level by eye I suspect has a larger error than using a level.
I can't immediately think of a way of setting 2nd and 3rd axis in a similar manner, but that doesn't mean there isn't one...

*Another bugbear I have with this entire process that I'll mention is using the string to line things up or set the bow level.
For example using a device like the the one here (again overpriced, and with the audacity to use elastic bands).
Now, your string 'may' be vertical, but there's a good chance it isn't due to the cam system and lean etc.
There are always faces on the riser that are machined flat, however, so I always recommend people use these as I do in images 4&5 above.
 


geoffretired

Supporter
Supporter
Thanks for all the details.
Just to clarify, using a parallel card is just a card, no lines on it. Usually, a piece of card about 3/4" wide and 6" long, can be fixed to the scale bar with tape, so one edge is pressed onto the upright edge of the scale bar. The other edge will be pretty close to lining up with the bowstring when viewed from behind the string. With light behind the sight and the card lined to the string a slight move of the head can produce a very thin strip of brightness between the two. Even if the bow moves if you hold it in your hands, the slit of light will show clearly as parallel or tapered. It is a well used technique in wood work to check if the wood is as square as the Try square used for measuring 90 deg.
To big advantage if anyone tries it, is there are no clamps at all. Having a steady hand is not that important either. When viewing against a light, the eye can pick up on the taper or parallel, in an instant. Even if the bow is moving, the bright strip moves with the bow and the shape of the bright strip remains tapered or parallel. I suppose it is similar to using contrasting coloured strip across bow limbs to look for twists. The upper edges of the strips look parallel; or don't. You just need to make sure they don't fall off the limbs while you eyeball them. heehee
 


Top